This application makes reference to incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from applications for A METHOD FOR MAINTAINING A SEAT LIFE OF A BUTTERFLY VALVE AND AN APPARATUS THEREOF earlier filed in the Korean Industrial Property Office on the 26th of Jan. 1999 and there duly assigned Ser. No. 2467/1999, and for METHOD AND APPARATUS FOR OPENING AND CLOSING OF BALL VALVE earlier filed in the Korean Industrial Property Office on the 24thof Jan. 2000 and there duly assigned Ser. No. 3219/2000.
1. Field of the Invention
The present invention relates to an apparatus and a method for opening/closing a valve, and more particularly, an apparatus and a method for opening/closing a valve, in which a position of a seat for maintaining an airtightness of a valve member is varied before or after an opening/closing operation of the valve member, wherein the valve member is rotated in a fluid passage of a valve body in order to open/close a valve.
2. Description of the Related Art
Generally, a ball type valve or a disk type valve is provided a valve seat which is made of a rubber and a Teflon resin or other elastic material. The valve seat is assembled into a fluid passage of a valve body. And a valve member such as a ball or a disk is rotatably mounted by a rotational shaft in an inner side of the valve seat. The shaft is connected with an actuator for driving the shaft so as to open/close the fluid passage by the operation of the actuator.
In this case, however, since an outer face of the valve member is contacted with the valve seat upon the opening/closing operation of the valve member, if the opening/closing operation of the valve member is repeatedly performed over a long time, a partial side wear is occurred in the valve seat. Therefore, an airtightness between the valve member and the valve seat is not maintained, thereby occurring a defect in the valve.
Further, since the valve seat is sealingly contacted with the outer face of the valve member in order to maintain the airtightness between the valve seat and the valve member, the valve member can not facilely rotated to open/close the valve upon the opening/closing operation of the valve member due to a friction force between the outer face of the valve member and an inner face of the valve seat.
It is therefore an object of the present invention to extend the life span of the valves seat and maintain the airtightness of the ball valve.
It is other object of the present invention to enable the ball valve to be driven by a weak driving force.
To achieve the above objects and other advantages, there is provided a method for opening/closing a valve including the steps of varying a position of a seat assembled into an inner side of an open passage of a valve body so as to be separated from a turning radius of a valve member for opening/closing the fluid passage, rotating the valve member in a forward or reverse direction by an actuator, rotating the valve member in the forward direction and opening the fluid passage, rotating the valve member in the reverse direction, and returning the position of the seat so that an inner side of the seat is sealingly contacted with an outer face of the valve member and closing the fluid passage.
The seat is fixed to a seat sliding guide, and the position of the seat is varied by a movement of the seat sliding guide using a pneumatic pressure. The seat is fixed to a seat sliding guide, and a magnetic member is provided in a side of the seat sling guide and the valve body and a side cover so that the position of the seat is varied by a magnetic force of the magnetic member.
Preferably, the seat is fixed to a seat sliding guide, a magnetic member is provided in a side of the seat sling guide and the valve body and a side cover so that the position of the seat is varied by a magnetic force of the magnetic member.
The valve includes a valve body, a seat supported by a side cover and assembled in an open passage of the valve body, an opening/closing ball rotatably mounted via a rotational shaft to an inner side of the seat and rotated in a forward or reverse direction by an actuator connected with the rotational shaft so that the valve is opened or closed first and second air supplying passages formed on the valve body, and a ring-shaped air passage communicated with the first and second air supplying passage and provided in an inner side of the valve body, wherein the seat is mounted to the valve body so as to be spaced-apart at a desired distance, and an airtightness of the ring-shaped air passage is maintained by a O-ring.
The valve includes a plurality of permanent magnets respectively provided in one side of one of the first and second air passages, one side of the valve body and a side of the seat sliding guide corresponding to the valve body.
The valve includes a valve body, a seat supported by a side cover and assembled in an open passage of the valve body, and an opening/closing ball rotatably mounted via a rotational shaft to an inner side of the seat and rotated in a forward or reverse direction by an actuator connected with the rotational shaft coupled to the ball so that the valve is opened or closed, wherein the valve body is formed with a ring-shaped air passage, the seat and seat sliding guide are mounted to the ring-shaped air passage so as to be apart from the valve at a desired distance, a plurality of permanent magnets are provided on both sides of the seat sliding guide, in which the seat is fixed, so that polarities of the permanent magnets adjacent to each other are different and also other permanent magnets are provided on an outer face of the valve body and an inner side of the side cover, which are correspondent with the permanent magnets of the seat sliding guide so that polarities of the permanent magnets adjacent to each other are different.
The valve apparatus includes a valve body, a seat supported by a circular cover ring and assembled in an open passage of the valve body, and an opening/closing disk rotatably mounted via a rotational shaft to an inner side of the seat and rotated in a forward or reverse direction by an actuator connected with the rotational shaft coupled to the disk so that the valve is opened or closed, wherein the valve body is provided with a first and second air supplying passage, a ring-shaped air passage communicated with the first and second air supplying passage is provided in an inner side of the valve body, the seat is mounted to the valve body so as to be apart at a desired distance and an airtightness of the ring-shaped air passage is maintained by a O-ring.
Preferably, the apparatus according to the present invention further comprises an elastic member which is provided in one side out of the first and second air passage and between the valve body and seat or between the circular cover ring and the seat.